Process for the dyeing of mixtures of cellulose and polyacrylonitrile fibers from one bath

ABSTRACT

1. A PROCESS FOR EXHAUST DYEING FROM A SINGLE BATH A FIBROUS MATERIAL CONTAINING A MIXTURE OF CELLULOSE FIBERS AND POLYACRYLONITRILE FIBERS WITH A REACTIVE DYESTUFF HAVING AT LEAST ONE VINYLSULFONE REACTIVE GROUP OR ONE GROUP THAT FORMS A VINYLSULFONE REACTIVE GROUP IN ALKALINE MEDIUM AND WITH A NON-REACTIVE BASIC DYESTUFF, WHICH COMPRISES HEATING SAID MATERIAL AT A TEMPERATURE BETWEEN ABOUT 20*C AND ABOUT 80*C IN AN AQUEOUS DYEBATH THAT CONTAINS SAID REACTIVE DYESTUFF, A NON-IONIC DISPERSING AGENT AND AND ALKALINE AGENT TO ADJUST THE PH OF SAID DYEBATH TO BETWEEN ABOUT 9 AND ABOUT 12 UNTIL SAID REACTIVE DYESTUFF IS FIXED ON THE CELLULOSE FIBERS, ADDING TO SAID DUEBATH SAID NON-REACTIVE BASIC DYESTUFF AND A FREE ORGANIC ACID OR INORGANIC ACID TO ADJUST THE PH OF SAID DYEBATH TO BETWEEN ABOUT 3.5 AND ABOUT 6, AND HEATING SAID MATERIAL IN SAID DYEBATH AT A TEMPERATURE BETWEEN ABOUT 95*C. AND ABOUT 130*C. UNTILS SAID BASIC DYESTUFF IS FIXED ON THE POLYACRYLONITRILE FIBERS.

United States Patent U.S. Cl. 8--21 A 9 Claims ABSTRACT OF THE DISCLOSURE Process for the dyeing of mixtures of cellulose and polyacrylonitrile fibers from one bath with reactive dyestuffs of the vinylsulfone type and cationic dyestuffs, wherein the goods are treated with a bath containing a reactive dyestuff, alkalis and non-ionic dispersing agents at 20 to 80 C. and wherein subsequently free acid and a cationic dyestuff are added and the dyeing is completed in an acid medium at 95 to 130 C. Compared with the hitherto used two-bath processes the process of the present invention has the particular advantage of saving 25 to 50% of dyeing time. a

This application is a continuation application of pending application Ser. No. 864,563, filed Oct. 7, 1969, now abandoned.

It is known that the dyeing of textile materials consisting of mixtures of cellulose and polyacrylonitrile fibers from one bath with reactive and cationic dyestuffs is connected with difficulties. These difficulties are due to the different dyeing conditions which are required for each of the two dyestuff classes.

Cationic dyestuffs in general require long dyeing times and the use of dyeing temperatures of above 95 C.

Furthermore, for dyeing, cationic dyestuffs are applied from an acid medium, because when applied in the alkaline range, some of these dyestuffs tend to precipitate, changes of shade occur and the fastness properties of the dyeings are impaired.

Furthermore, cationic dyestuffs may form with the anionic reactive dyestuffs an addition compound which may provoke precipitation of the dyestuff and deteriorate the fastness to rubbing of the dyeings.

Reactive dyestuffs require alkaline conditions to enable the reaction with the hydroxyl groups of the cellulose fibers. With too long a dyeing time, however, especially at temperatures exceeding 95 C., the dyestuff-fiber bond is split by the action of the alkalis, which entails reduction of the color yield on the goods.

Now, we have found that the above-described disadvantages can be avoided and that mixtures of cellulose and polyacrylonitrile fibers can be dyed from one bath with reactive and cationic dyestuffs, by treating the said materials, in the same bath, at first at temperatures in the range of from about 20 C. to 80 C. with an aqueous bath which contains, in addition to the reactive dyestuff, alkalis and non-ionic dispersing agents and, after addition of free acid and of the cationic dyestuff, completing the dyeing in an acid medium, in general in a pH-range of from 3.5 to 6, at temperatures in the range of from about 95 C. to 130 C.

The process of the invention permits to adjust the pH- values of the dyebath in such a manner that they correspond to the respective fixing conditions of the reactive and cationic dyestuffs, without it being necessary to use 3,843,319 Patented Oct. 22, 1974 separate baths. It is extraordinarily surprising that, at the high temperatures used in an acid medium, hydrolysis of the bond between reactive dyestuff and fiber and therewith a loss of color yield do not occur. In addition, the quantities of electrolyte required in the dyeing of cellulose fibers with reactive dyestuffs and the reactive dyestuffs which remain in the bath and are not fixed on the cellulose fibers act as retarders for the cationic dyestuffs used for the dyeing of the polyacrylonitrile fibers. Thus, the application of the usual retarders used in the dyeing of polyacrylonitrile fibers with cationic dyestuffs is not necessary. By the simultaneous use of a non-ionic dispersing agent on the basis of oxalkylates and/or polyglycols, the water-insoluble addition compounds of cationic dyestuffs and anionic reactive dyestuffs can be maintained in a fine dispersion so that precipitations and deteriorations of the fastness to rubbing of the dyeings are avoided.

For carrying out the process of the present invention, the textile material is treated for 10 to minutes, preferably for 20 to 60 minutes, with the bath which has been heated to about 20-80 C., preferably to about 4060 C., and which contains the non-ionic dispersing agent, the dissolved reactive dyestuff and the agent having an alkaline action, during which time the reactive dyestuff is first fixed onto the cellulose fiber. Then the cationic dyestuif which has been dissolved with free acid and hot water is added. Thereby, the pH is adjusted to a value in the range of from 3.5 to 6, preferably to 4.5 to 5.5.

The dyebath is then heated to a temperature in the range of from to C. and the goods are left at this temperature for 30 minutes to 3 hours, preferably 45 to 90 minutes. During this time, the cationic dyestuff is fixed on the polyacrylonitrile fiber. After the dyeing, the goods are rinsed and soaped and then treated in the usual manner.

Over the hitherto used two-bath processes, the process of the invention for the dyeing of mixtures of cellulose and acrylonitrile fibers from one bath has the particular advantage of saving 25 to 50% of dyeing time. Another advantage becomes evident when the process is used in the dyeing with program-controlled dyeing apparatus. After charging of the dyeing apparatus and introduction of the cationic dyestuff dissolved ,with acid and hot water into the supplementary tank connected to the dyeing apparatus, the dyeing program can proceed automatically, without it being necessary to employ an opeartor. In contradistinction thereto, in the conventional two-bath process the dyeing apparatus has to be charged two times.

As reactive dyestuffs, there may be used in the process of the invention those organic dyestuffs which contain as reactive component at least one vinyl-sulfone group or at least one group which forms a vinyl-sulfone group upon the action of the alkaline agents during dyeing.

As reactive dyestuffs, there are especially suitable those of the series of the anthraquinone, azo and phthalocyanine dyestuffs; the azo and phthalocyanine dyestuffs may be metal-free or metalliferous. Of the class of groupings which can be converted during the treatment with alkaline agents into a vinyl-sulfone group which is capable of reacting with the cellulose fiber, there may be mentioned, as examples, in particular the sulfuric acid esters and thiosulfuric acid esters of B-hydroxy-ethyl-suh fone groups. Examples of reactive dyestuffs of the kinds cited above are those described in U.S. Pats. No. 2,670,265; No. 2,657,205; No. 3,197,456; No. 3,349,097; No. 3,324,151; No. 3,261,823; and No. 3,417,074.

As cationic dyestuffs to be used in the process of the present invention, those of the series of the azo, azomethine, methine, anthraquinone, nitro, diand tri-phenylmethane, phenazine, oxazine, thiazine, xanthene and quinophthalone dyestuffs may be employed. Suitable 3 cationic dyestuffs are those described in Colour Index, second edition (1956), vol. 1, pages 1617 to 1653, the 1963 Supplement, pages S149 to S177 and corresponding Additions and Amendments, No. 1 (Sept., 1963) to No. 22 (Jan, 1969).

The alkaline agents to be added to the dyebaths according to the invention may be used in the quantities generally applied in practice in the dyeing with reactive dyestuffs. The content of alkali in the baths should be so high as to allow adjustment of the pH-value of a value in the range of from 9 to 12 and maintaining it during the fixation of the reactive dyestuffs. As alkalis, inorganic compounds having an alkaline action such as potassium carbonate, sodium bicarbonate, sodium triphosphate, sodium diphosphate, sodium hydroxide, sodium silicates, the corresponding potassium compounds or mixtures of these alkaline compounds, but preferably sodium hydroxide solution, are suitably used.

As free acids which are required in the process of the invention for establishing the acid fixing conditions for the cationic dyestuffs, there may be used mineral acids such as hydrochloric acid, sulfuric acid or phosphoric acid, or organic acids such, for example as acetic acid or formic acid. Mixtures of these acids may also be used. However, acetic acid is preferably used. The quantity of free acid to be added to the dyebaths after fixation of the reactive dyestuffs depends in the first instance on the alkali content of the bath and therewith indirectly on the total quantity of reactive dyestuif used, which in turn is dependent on the mixing ratio of the portions of cellulose and polyacrylonitrile fibers in the textile materials to be dyed.

As non-ionic dispersing agents, there may be used according to the invention either oxethylation products which are derived from fatty acid derivatives such as the fatty amines, fatty acid amides or fat alcohols, the oxethylation products of the fat alcohols being preferred, for example the addition products of 1 mol of stearyl alcohol and 25 mols of ethylene oxide or of 1 mol of oleyl alcohol and 22.5 mols of ethylene oxide, or higher polyglycols having a mean molecular weight in the range of from 1500 to 6000, or mixtures of these products. A mixture of the reaction product of 1 mol of stearyl alcohol and 25 mols of ethylene oxide, and polyglycol having a molecular weight of 6000, in a mixing ratio of 1:1 to 8:1, preferably 4:1, is preferably used.

Furthermore the dyebaths may additionally contain the usual electrolytes, wetting or dispersing agents.

The textile material to be dyed according to the process of the present invention and which consists of mixtures of native or regenerated cellulose fibers and fibrous materials of polyacrylonitrile, may have the most various forms, for example the form of flocks, slivers, yarns, fabrics or knit fabrics.

The following Examples illustrate the invention.

EXAMPLE 1 I A mixed fabric consisting of polyacrylonitrile and staple fibers in a mixing ratio of 50:50 was dyed in the form of yarns on cheeses, at a goods to liquor ratio of 1:15, for 30 minutes, on a high temperature beam dyeing apparatus, at 60 C., with a bath which contained per liter of water, 0.58 g. of the reactive dyestutf of the formula Nl-Pc v (EUR:

Ni-Pc=Nickelphthalocyanine,

4 and 0.63 g. of the reactive dyestuff of the formula S O zCH2CHz-O S 03H in commercial form and composition. The bath furthermore contained, per liter of water,

2.0 ml. of sodium hydroxide solution of 38 Be'.,

50.0 g. of sodium sulfate,

0.4 g. of the reaction product of 1 mol of stearyl alcohol and 25 mols of ethylene oxide, and

0.1 g. of a polyglycol having a molecular weight of 6000.

Then, there were added to the dyebath, per liter of the bath described above,

5.0 ml. of 60% acetic acid, 0.07 g. of the cationic dyestuff of the formula CzH\ N -N 0g V \C2H5 and 0.36 g. of the cationic dyestuif of the formula r CCHa I I 0H,

The dyebath was heated to 106 C. and the yarn was left for 60 minutes at this temperature. The dyed yarn was then rinsed and soaped, rinsed again and dried.

A green dyeing was obtained in which the polyacrylonitrile and staple fiber portions of the mixed yarn were well dyed tone-in-tone.

EXAMPLE 2 A textile material as that described in Example 1 'was dyed in a manner analogous to that described in the said Example, but using as dyestuffs 0.7 g. of the reactive dyestulf of the formula (H) NHz @A Y A bi-color dyeing was obtained on the mixed yarn in which the cellulose fiber portion had a blue shade and the polyacrylonitrile fiber portion had an orange shade.

We claim: 4

1. A process for exhaust dyeing from a single bath a fibrous material containing a mixture of cellulose fibers,

and polyacrylonitrile fibers with a reactive dyestuff having at least one vinylsulfone reactive group or one group that forms a vinylsulfone reactive group in alkaline medium and with a non-reactive basic dyestutf, which comprises heating said material at a temperature between about 20 C. and about 80 C. in an aqueous dyebath that contains said reactive dyestutf, a non-ionic dispersing agent and an alkaline agent to adjust the pH of said dyebath to between about 9 and about 12 until said reactive dyestutf is fixed on the cellulose fibers, adding to said dyebath said non-reactive basic dyestuff and a free organic acid or inorganic acid to adjust the pH of said dyebath to between about 3.5 and about 6, and heating said material in said dyebath at a temperature between about 95 C. and about 130 C. until said basic dyestulf is fixed on the polyacrylonitrile fibers.

2. A process according to claim 1 wherein said cellulose fibers are dyed at a temperature between about 40 C. and about 60 C.

3. A process according to claim 1 wherein said poly acrylonitrile fibers are dyed at a pH between about 4.5 and about 5.5.

4. A process according to claim 1 wherein said nonionic dispersing agent is an oxyethylation product of a fatty amine, fatty amide or fatty alcohol or a polyglycol of average molecular weight between about 1500 and about 6000.

5. A process according to claim 1 wherein said reactive dyestuff is an anthraquinone, an am or a phthalocyanine dyestuff.

6. A process according to claim 1 wherein said group that forms a vinylsulfone reactive group in alkaline medium is a sulfuric acid ester or a thiosulfuric acid ester of a B-hydroxy-ethyl-sulfone group.

References Cited UNITED STATES PATENTS 8/1965 Kuth et a1. 821 A OTHER REFERENCES Cheetham: Dyeing Fibre Blends, Pub. 1966, pp. 200- 201 and 224225, pub. by D. Van Nostrand Co., Ltd., London.

DuPont: Textile Fibers Technical Information, Multifiber Bulletin X-l13, October 1959, 3 pages.

Keaton et al.: J. Soc. Dyers and Col., June 1964, pp. 312-322.

LEON D. ROSDOL, Primary Examiner B. H. HESS, Assistant Examiner U.S. Cl. X.lR. 

1. A PROCESS FOR EXHAUST DYEING FROM A SINGLE BATH A FIBROUS MATERIAL CONTAINING A MIXTURE OF CELLULOSE FIBERS AND POLYACRYLONITRILE FIBERS WITH A REACTIVE DYESTUFF HAVING AT LEAST ONE VINYLSULFONE REACTIVE GROUP OR ONE GROUP THAT FORMS A VINYLSULFONE REACTIVE GROUP IN ALKALINE MEDIUM AND WITH A NON-REACTIVE BASIC DYESTUFF, WHICH COMPRISES HEATING SAID MATERIAL AT A TEMPERATURE BETWEEN ABOUT 20*C AND ABOUT 80*C IN AN AQUEOUS DYEBATH THAT CONTAINS SAID REACTIVE DYESTUFF, A NON-IONIC DISPERSING AGENT AND AND ALKALINE AGENT TO ADJUST THE PH OF SAID DYEBATH TO BETWEEN ABOUT 9 AND ABOUT 12 UNTIL SAID REACTIVE DYESTUFF IS FIXED ON THE CELLULOSE FIBERS, ADDING TO SAID DUEBATH SAID NON-REACTIVE BASIC DYESTUFF AND A FREE ORGANIC ACID OR INORGANIC ACID TO ADJUST THE PH OF SAID DYEBATH TO BETWEEN ABOUT 3.5 AND ABOUT 6, AND HEATING SAID MATERIAL IN SAID DYEBATH AT A TEMPERATURE BETWEEN ABOUT 95*C. AND ABOUT 130*C. UNTILS SAID BASIC DYESTUFF IS FIXED ON THE POLYACRYLONITRILE FIBERS. 